According to some at GTA Forums, there are some connections between certain actors and Rockstar developers, meaning that they are probably working on the sequel Red Dead Redemption 2.
Gabriel Sloyer, who worked online last on Grand Theft Auto V, has made some connection with actors from the original Red Dead Redemption, which include Steve J. Palmer (Bill Williamson), Benjamin Byron Davis (Dutch Van Der Linde) and Rob Wiethoff (John Marston, the hero of the original game). Also, Peter Blomquist is probably part of this crew too, as he was Dr. Harlan Fontaine in L.A Noire.
There is more to it. Lindsay Perry, another actor from Grand Theft Auto V, connected with Davis, together with Roget Clark, who is rumored to be on the team for Red Dead 2. It is not confirmed yet, about any of the returning characters for the sequel.
Nothing is confirmed by Rockstar Games, but we are all paying attention to the title, and its release in 2018.
Red Dead Redemption 2 will be released in SPring 2018 for Xbox One and PS4.